that's bit confusing machan. isn't it?
all I know is "pin" and "kusal" is two different things.
"pin" is what we collect to continue our life cycle ("bhawaya"). we consume this thing call "pin" while we live.
but "kusal" is for terminate the cycle.
ys bro..
we consume out stack of pin while we live that's true..
but to consume first you must have them in your custody..
so kusal is the way which aids you to collect pin.
by committing kusal you will earn pin and by committing akusal you will be marched off to the repercussions.